Human pseudotail associated with diastematomyelia: A case report and literature review

The human tail is just the distal remnant coccygeal appendage of the embryonic tail. It may be formed by muscle or fatty tissue and by cartilage or bone covered with skin. Many cases may be associated with spinal dysraphism. The case presented here is of a child with a human pseudotail in the region of the lumbar spine associated with diastematomyelia.

A 4-year-old girl presented with pain and bulging in the lumbar spine. On neurologic examination, there were no motor or sensory deficits, the urinary and anal sphincters were normal. Imaging examinations (computed tomography and magnetic resonance imaging) showed fusion of L1/L2 with a bony septum separating two dural sacs and a bony caudal appendage articulating with the posterior elements of L2. The patient was treated surgically and progressed well. Regression of the human embryonic tail occurs in the 8^th week of pregnancy. In some cases, a caudal remnant stays in the coccygeal region or just above it. The association with spinal dysraphism may be present, and surgical treatment will depend on the complexity of the anomaly.

We describe an unusual case of a human tail above the coccyx (lumbar spine region) and, despite the association with a type of spinal dysraphism (diastematomyelia), the patient had a good neurological course after surgical treatment.